Given efficacy in first act, consent follows infallibly
Thesis CXXXV. Whatever this dependence of efficacious grace on free choice in second act may be, on their view the efficacy of grace is such that, once it is in place in first act, the effect follows infallibly, namely the consent and cooperation of free choice. For an aid is called efficacious when it 'moves the will efficaciously and infallibly to give its consent, and makes it act', as the same Peter of Saint Joseph puts it in the disputation cited, number 61. Given that efficacy of the divine aid, which it has from God alone and prior to the will's consent, it can never happen that a person fails to do what such aid moves him to do.
Conversely, take that efficacy away, and however much sufficient grace is supposed, the good work for which it is called sufficient simply cannot follow. Here too they part from Molina. On his assumptions, whatever grace of God is given ahead of the will's actual consent, the effect it is directed to may follow or may not, and the outcome is infallible neither way.
Latin
CXXXV. Qualiscunque tamen sit illa dependentia gratiae efficacis, quoad actum secundum, a libero arbitrio; nihilominus ex eorum sensu, efficacia gratiae talis est, ut ea posita in actu primo, infallibiliter sequatur effectus, id est, liberi arbitrii consensus & cooperatio: siquidem auxilium illud efficax esse dicitur, quod efficaciter, & infallibiliter voluntatem movet ad consensum eliciendum, & facit ut faciat. Ut loquitur idem Petrus a Sancto Joseph in citata disputatione num. 61. Adeo ut supposita efficacia illa auxilii divini, quam habet a solo Deo, & antecedenter ad voluntatis consensum, nunquam contingere possit, ut homo non faciat illud ad quod ejusmodi auxilio movetur. Sicut ex adverso remota tali efficacia, quantumcunque gratia sufficiens supponatur, prorsus contingere nequit, ut sequatur illa bona operatio, ad quam sufficiens dicitur. Qua in re quoque a Molina discedunt, juxta cujus hypotheses, quacunque Dei gratia actualem voluntatis consensum antecedente posita, fieri potest ut effectus, ad quem ordinatur gratia, vel sequatur, vel non sequatur: nec in alterutram partem eventus infallibilis est.